1. Field of the Invention
The invention relates to a method for mutually aligning bodies, in particular for the parallel alignment of shafts, rollers and the like, and to a position measuring sensor for carrying out the method.
To date, optical measuring arrangements such as theodolites, autocollimators, interferometers and lasers and, by way of further ancillary means, markers, targets, pentaprisms, ridge prisms, triple prisms, mirrors, detectors, stands and the like have been used in a very time consuming manner for angle measurement for the purpose of the mutual alignment of bodies, e.g. of axles, rollers, rolls, spindles, rotary furnaces and the like, their drives such as chains, belts, transmissions, universal joints and the like as well as their associated carrier elements such as support frame, machine beds, foundations etc., with measurement accuracies of below 1 mm/m.
2. Description of Related Art
The object of the invention is to specify a method by which the angle measurement of bodies to be mutually aligned can be performed with an expenditure of time, and in some cases also a design complexity, which is substantially less than in the case of the known devices and ancillary means for this purpose.
In contrast to the known methods, in which as a rule a plurality of devices and ancillary means have to be secured to the bodies to be measured, aligned with respect to one another and then moved in common with bodies in a measurement cycle, in the case of the inventive method it is merely necessary for a single position measuring sensor which is simple to handle and which is equipped with an optical gyroscope to be applied in a few measurement positions to in each case two bodies to be aligned with respect to one another and to be read off directly or electronically, with respect to gyro angle and inclination, in order to be able to establish whether any position corrections at all, and, if so, which ones are necessary in order to achieve the desired alignment The operator's measurement time required for this is far shorter than that which is necessary when using the known devices and ancillary means A reduction in the operator's measurement time of up to 95% is to be expected.
The invention is based on the finding that optical gyroscopes are distinguished by a very low noise level thus, by way of example a known fiber optic gyroscope (referred to in the English literature in abbreviated form as FOG) has a noise level of only 0.1.degree. per root hour when using a fiber ring having a diameter of approximately 80 mm--and that, on the basis of such a low noise level with the observance of a time interval measuring in the order of magnitude of a few seconds for the application of the measuring sensor to the two bodies to be aligned for the purpose of obtaining a pair of measured values, it is possible to obtain measured values which are absolutely accurate enough, because in this gyroscope resetting time, which although short is sufficient for practical purposes, a gyroscope which is appropriately dimensioned according to the given possibilities only drifts by a few grad, which is sufficient for most measurement problems.
The accuracy of measurement is all the greater, the more rapidly and/or more frequently the measuring sensor can be reset with its optical gyroscope
A further object of the invention is to provide a position measuring sensor for determining the spatial position of two bodies with respect to one another, which sensor has a high accuracy of measurement for angle measurements and is particularly suitable for carrying out the inventive method.
In the text which follows, the invention is explained in even greater detail with the aid of the drawing, by reference to an illustrative embodiment.